DESCRIPTION: The long term goal of this project is to develop conditions that will permit normal development of oocytes matured, fertilized and developed to the blastocyst stage in vitro. Since conditions for swine have already been developed that can result in development from the 1-cell stage to the blastocyst stage with subsequent term development, here the investigators chose to focus upon oocyte maturation conditions. The overall thesis is: In vitro matured oocytes are less developmentally competent that in vivo matured oocytes. It is proposed to evaluate a number of parameters, using oocytes or embryos derived from both in vivo and in vitro maturation, that may be predictive of subsequent development in domestic swine. It is known that embryos derived from in vitro maturation rarely result in term development. Thus the first goal is to establish baselines and describe differences between in vivo and in vitro maturation. Depending upon the differences between in vitro and in vivo that are noted, the maturation system will be modified to address that concern directly. To that end the following endpoint in material derived from both in vivo and in vitro maturation will be investigated: 1) glutathione content, 2) pronuclear formation, 3) both histone H1 kinase and MLCK activity, 4) the ability to respond to IP3 or fertilization with a single or multiple [Ca2]1 transients(s), respectively, 5) blastocyst formation, 6) fetal development, 7) quality and rate of protein synthesis, and 8) expression of mRNA encoding trophectoderm specific genes and their secretory products. The last specific aim is designed to non-invasively evaluate the developmental competence of blastocyst stage embryos prior to transfer. After specific differences in these parameters are noted, then modifications to the maturation conditions will be made and the specific parameter remeasured, and confirmed by producing offspring.